/Engine/Source/Editor/UnrealEd/Public/EditorViewportClient.h
Attempts to intelligently drop the given objects in the viewport, using the given mouse coordinates local to this viewport
virtual bool DropObjectsAtCoordinates ( int32 MouseX, int32 MouseY, const [TArray](API\Runtime\Core\Containers\TArray)< [UObject](API\Runtime\CoreUObject\UObject\UObject) * > & DroppedObjects, [TArray](API\Runtime\Core\Containers\TArray)< [AActor](API\Runtime\Engine\GameFramework\AActor) * > & OutNewActors, bool bOnlyDropOnTarget, bool bCreateDropPreview, bool bSelectActors, [UActorFactory](API\Editor\UnrealEd\ActorFactories\UActorFactory) * FactoryToUse )